Field of the Invention
The present invention relates to a technique for carrying out processing over a plurality of semiconductor substrates, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display, a glass substrate for a photomask, a substrate for an optical disk or the like (which will be hereinafter referred to as a “substrate”).
Description of the Background Art
There are various substrate processing apparatus for carrying out processing over a substrate. For example, the substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2009-146975 has the structure in which the indexer cell for accumulating the unprocessed substrate and the processed substrate and the washing processing cell for carrying out scrub washing processing over the substrate are connected to each other through the substrate transferring portion. The special transport robot for each cell is disposed in the indexer cell and the washing processing respectively.
In the substrate processing apparatus of this type, an inverting portion for inverting a front surface and a back surface of a substrate is sometimes provided in the device to prepare for the case in which the back surface of the substrate is washed. For example, in the substrate processing apparatus disclosed in the Japanese Patent Application Laid-Open No. 2009-146975, the inverting portion is disposed in the washing processing cell. Moreover, Japanese Patent Application Laid-Open No. 10-321575 (1998) describes the inverting and washing unit for inverting the substrate and washing the back surface thereof. Furthermore, Japanese Patent Application Laid-Open No. 2009-252888 and Japanese Patent No. 4287663 describe the structure in which the front surface and the back surface of the substrate are inverted through the relay portion between the transport robots.
In the structure of the device in which the inverting portion for inverting the front surface and the back surface of the substrate is disposed in the relay portion between the transport robots, the substrate delivered into the inverting portion by one of the transport robots can be transferred by the other transport robot after the inversion. In other words, the functioning portion for inverting the substrate can be used as a portion for transferring the substrate between the transport robots. According to the structure, for example, it is possible to decrease the number of steps of the transport robot as compared with the device structure in which the inverting portion is disposed in a position where only one of the transport robots can give access. As a result, it is possible to enhance a throughput of the substrate processing apparatus.
On the other hand, it is necessary to shorten a standby time for each transport robot as greatly as possible in order to suppress reduction in the throughput of the substrate processing apparatus. For example, when the transport robot tries to send the substrate to the transferring portion, the transport robot is to wait for the other transport robot to transport the substrate from the transferring portion if the transferring portion is full of the substrate. In order to avoid such a situation as greatly as possible, it is preferable that the transferring portions should be provided in the relay portion between the transport robots.
In recent years in which increase in a size of the substrate progresses, a space required for inverting the substrate is enlarged. Consequently, a size of the inverting portion is being increased. For this reason, in the case in which the relay portion is provided with necessary numbers of transferring portions and inverting portions in lamination, for example, a travel distance (a stroke) in a vertical direction of a hand of the transport robot is increased depending on increase in a height dimension of the inverting portion, which is directly linked to reduction in the throughput.